/Engine/Plugins/Online/OnlineSubsystem/Source/Public/Interfaces/OnlineExternalUIInterface.h
Delegate executed by the requesting system when a supporting login flow browser window is asked to handle the request
typedef TMulticastDelegate_FourParams< void, const [FString](API\Runtime\Core\Containers\FString) &, const [FOnLoginRedirectURL](API\Plugins\OnlineSubsystem\Interfaces\FOnLoginRedirectURL) &, const [FOnLoginFlowComplete](API\Plugins\OnlineSubsystem\Interfaces\FOnLoginFlowComplete) &, bool & > FOnLoginFlowUIRequired